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Launching the Lake Lander

PLLers (l to r) Trey Smith, Geoff Saville, Liam Pedersen and Chris Haberle celebrate the successful application of wire and plastic tie-wraps to the task of securing the guts of PLL’s profiler to its pontoon. Credit: XenoQuest Media

The Planetary Lake Lander is a reality! Yesterday it was assembled at Launch Point on the southwest shore of Laguna Negra, and today it was sailed to its initial mooring point about 100 meters offshore, near PLL Base Camp. Major accomplishment.

The lake lander has four main components. The pontoon is the floating platform to which everything else is attached. The sonde is a package of underwater sensors that can be lowered to different depths. The weather station measures temperature, barometric pressure, wind speed and direction. Finally, there is the profiler. It contains a winch to lower and raise the sonde, a package of electronics to collect and store data, and radios to transmit that data to PLL scientists.

The sonde has a number of sensors on it, each to study a different characteristic of the subsurface lake environment. It monitors water temperature; pH; dissolved oxygen; conductivity, an indicator for the saltiness of the water; turbidity, or water cloudiness; and the amount of algae present.

Every hour, the PLL profiler sends commands to the sonde to descend through the water column, collecting data as it goes. For now, this data gets sent to the Robo Dome at Base Camp. Beginning in a couple of weeks, once the PLL team packs up and leaves, the profiler will transmit its information via satellite to NASA Ames Research Center in California.

By combining underwater and weather data, PLL scientists will be able to construct a model of how atmospheric conditions interact with subsurface conditions. This model will lay a foundation for spotting events that deviate from the norm.

The model will also enable engineers from the Intelligent Robotics Group (IRG) at Ames to write software that will ultimately transform the PLL from a passive data-collection device into an intelligent, autonomous robot. Their goal for the three-year project is to infuse PLL with decision-making ability so that, without human intervention, it can spot events of particular scientific interest and alter its data-collection routine – taking more-frequent measurements, for example – to study these events in greater detail.

Of note: although the Planetary Lake Lander does not yet have a name, the sonde attached to it does. It’s Jerry. Jerry? Yes, Jerry. It has an identical twin, Tom, which is not tied in to any communications capability and which currently gets moved around from one lake to another at the whim of scientists. While Jerry will spend the summer ascending and descending through the water column below the PLL platform, its information relayed back to Ames, Tom will be left in a single stationery position in one of the other nearby lakes, collecting data through the summer but unable to share what it learns until someone comes to retrieve it.

On his homemade vuvuzuela, Liam Pedersen (seated in chair) trumpets the arrival of the PLL at its temporary mooring site near PLL base camp. With him are Trey Smith (standing) and Chris Haberle. Credit: Henry Bortman

Also of note: The PLL is currently “parked” offshore near base camp, not because it is the most interesting spot in Laguna Negra, but rather because it’s easy to get to in case repairs need to be made. Later this week PLL team members will begin scouting the northern side of the lake, searching for the ideal spot for PLL’s summer home.

Oh, and still no shower, but we finally have a bathroom.

Quote of the day: “One real downside of our current dinner setup is the lack of portion control.”